# Renormalized stress tensor of a quantized massless scalar field in warped cosmological braneworld background

## TL;DR

This paper investigates the energy-momentum tensor of a quantum scalar field in a five-dimensional warped cosmological background, revealing how warping and a dynamic extra dimension influence matter creation and brane formation.

## Contribution

It introduces a renormalization approach for the energy-momentum tensor in warped cosmological spacetimes with a dynamic extra dimension, highlighting effects on matter creation.

## Key findings

- Warping and extra dimension dynamics affect energy and pressure densities.
- Created matter may accumulate to form thick branes.
- Adiabatic regularization effectively renormalizes the energy-momentum tensor.

## Abstract

Energy momentum tensor of a conformally coupled quantum scalar field in five dimensional warped cosmological spacetimes is studied. We look at situations where the four dimensional part represents a cosmological thick brane and the scale of the extra dimension is time dependent. Renormalization of the components of the energy momentum tensor is achieved using adiabatic regularization method. The resulting energy and pressure densities explicitly show the effects of warping and the dynamic extra dimension on the created matter. We discussed how the created matter may accumulate to form thick branes along the extra dimension.